Enthalpy of fusion

Enthalpy of fusion analysis involves measuring the amount of thermal energy required to change a material from a solid to a liquid state . This thermodynamic quantity, expressed in joules per gram (J/g) or kilojoules per mole (kJ/mol), is crucial for evaluating the purity , thermal stability , and crystalline structure of a product.

The enthalpy of fusion is measured using differential scanning calorimetry (DSC) , a reference method in materials science. By recording the heat absorbed during melting, DSC allows for the quantification of phase transitions and the identification of impurities or polymorphisms.

Experimental methods and protocols

The test is performed using a differential calorimeter that compares the heat flow between a sample and an inert reference subjected to the same temperature rise.
During melting, a net absorption of heat is recorded, the peak area of ​​which corresponds to the enthalpy of fusion.

The controlled parameters include:

• The heating speed ,
• The mass of the sample ,
• The gaseous atmosphere (nitrogen, air, helium),
• And the temperature range suitable for the matrix.

This method is standardized according to the ISO 11357 (for polymers) and ASTM E794 .

Industrial and scientific applications

The enthalpy of fusion is a key indicator in many fields:

• Cosmetics and pharmaceuticals : study of the thermal stability of waxes, butters, excipients, active ingredients.
• Agri-food and nutraceuticals : characterization of the crystallization of fats, cocoa butters, or plant extracts.
• Materials and polymers : evaluation of the degree of crystallinity, purity and structural changes after aging or heat treatment.
• Environment and chemistry : analysis of organic or mineral compounds to determine their thermal behavior.

The results allow us to determine:

• The melting temperature (Tf) ,
• The enthalpy of fusion (ΔHf) ,
• The degree of crystallinity (in the case of polymers),
• And the comparison of batches or formulations for quality control.

Related analyses

For a complete thermal characterization, YesWeLab recommends combining this study with:

• Thermogravimetry (TGA/ATG) to observe mass loss
• Enthalpy of vaporization for studying the liquid-gas transition,
• Heat capacity to determine the specific heat of the material.

Interpretation and significance of the results

The value of the enthalpy of fusion provides information about:

• Crystalline quality ( a low value often indicates impurities),
• The purity of a compound (correlation between Tf and ΔHf),
• The effects of thermal aging on stability,
• And the comparison between formulations (finished products, production batches, competitor samples).

This analysis is particularly useful for:

• control of raw materials ,
• Validation of thermal processes ,
• Optimizing the texture or blending of cosmetic or food products.

YesWeLab's expertise

YesWeLab provides you with its network of partner laboratories accredited to ISO 17025 and COFRAC , experts in advanced thermal analysis .

Thanks to the YesWeLab platform , you can:

• Order your thermal analyses online,
• Track your samples and results in real time
• Centralize your technical and regulatory reports.